Structure and function of red cell cytoskeleton.

Red cell shape changed reversibly depending on the ATP level, but the volume did not change. The surface area of both lipid bilayer and cytoskeleton network changed depending on the ATP level. Mild trypsin treatment of ghosts dissipated only ankyrin band and abolished the shape-and viscosity-change induced by CPZ and ATP+warming. Triton shells losing permeability barrier shrunk on addition of small concentrations of Ca2+ and swelled again on further addition of MgATP. The shells dissociated in 0.1mM MgATP and reassociated in 0.15M KC1. The nucleotide specificity was high. From diameters of cells, ghosts and shells at different pH and others, we propose that the erythrocyte shape is primarily decided by the cytoskeleton, the role of the lipid bilayer is complementary and thirdly the shape is modified by the relative volume of the cytoplasma.